The invention relates to a shaving apparatus having at least one circular cutting unit which comprises an external cutting member and an internal cutting member, which is rotationally drivable with respect to said external cutting member, which internal cutting member has cutting elements having cutting edges, which external cutting member is formed with a circular groove having a bottom wall and an upright inner and outer wall, the bottom wall and the outer wall having a plurality of slit-shaped hair-entry apertures oriented substantially radially, between which apertures lamellae are formed, which lamellae have counter-cutting edges for cooperation with the cutting edges of the cutting elements of the internal cutting member in order to sever hairs, the inner wall and a small part of the adjoining bottom wall forming an uninterrupted guard wall which precludes the entry of hairs.
Such a shaving apparatus is known from U.S. Pat. No. 2,280,052. The guard wall has a number of advantages such as a better support for the cutting elements, as a result of which the cutting edges remain sharp for a longer time, and a more robust construction, as a result of which the lamellae are less vulnerable. Moreover, it allows the hair-entry aperture in the outer wall of the groove to be deeper, as a result of which longer hairs are caught more effectively. A disadvantage of this guard wall in said known shaving apparatus is that during shaving hairs which come from the center of the cutting member are caught less satisfactorily because such hairs are very likely to be flattened and to be oriented transversely or at least obliquely across the hair-entry apertures and, as a consequence, are not caught in the hair-entry apertures.